Opisthokonta
by SkaraB
Summary: A short story about young Sherlock and Mycroft, crossposted from Archive of Our Own. Warning for descriptions of carrion, decay.


The English language is equipped with words like "hunger" and "lust" to describe specific desires. "Loneliness" could be defined as the longing for companionship; "ambition" the longing for success. But there is no single, suitable word for the longing to know the names of things.

Sherlock Holmes had looked for a word. He had read A through T of the Oxford English Dictionary before forgetting what he was searching for and finishing the rest purely out of curiosity.

**Curiosity**; noun: the desire to know or learn something. Casual, imprecise; as legitimately applied to his nurse's desire to know whether or not he had really washed his hands with soap as to his bone-deep need to understand why cloth burned and candle wax melted. Hardly the word he wanted.

At four years old, all Sherlock knew for certain was that this longing was an emotion closer to sadness than happiness, and combined the two in ways he could not articulate. He lived with this frustration like bellyache, until the cool April morning that it began to crystallize into resolve.

Sherlock sprawled on his stomach on the cement floor of their greenhouse. It was warm, and the damp soaked pleasantly through his shirtfront.

Weeds had begun sprouting in the unused clay pots, and Sherlock had placed one on the ground so that he could pluck each seedling by the roots, laying them in rows according to the shape of their leaves. Now he was breaking clumps of dirt apart between his fingers, and contemplating the white, feathering fuzz that grew all through the soil.

The east door squeaked open and snicked as it was closed- carefully, without slamming. Sherlock didn't need to turn around to know who had found him.

"There you are."

A pair of well-minded brogues shuffled into his periphery, and then his brother was kneeling beside him. Sherlock didn't say anything, only placed one of the conspicuously-fuzzed lumps of dirt on the ground between them.

"Ah." Mycroft swallowed a sigh at the sight of his blackened fingernails. "That's mycelium."

"I know," said Sherlock, who didn't.

A pause. "You haven't eaten any of it, have you?"

"No!"

"You know why I'm asking, Sherlock."

"I haven't, Mycroft. That was a-" His nose itched, and he rubbed it with his sleeve. "- that time was different. What's mycelium?"

"It's the main body of a fungus. The mushroom is only the fruiting body."

Sherlock nodded, brow puckering softly. "Does a poisonous mushroom have poisonous mice-"

"Mycelium. I - don't know." Mycroft frowned, corners of his mouth turning down in the way that made Sherlock want to argue.

"I didn't. I didn't even chew it."

He sounded so affronted that Mycroft chuckled. Then he stood, shoes scraping the pavement, loud in Sherlock's left ear. He brushed the knees of his trousers with thorough sweeps and threaded between the herb tables and the low cement pond to the tub sink, where he soaked his handkerchief. Sherlock greeted it with a put-upon sigh, but held out his hands, palms up.

"I found something interesting in the myrtle bushes, yesterday," Mycroft said, swiping the cloth between each of his brother's small fingers, with studious attention to the nails. "-Myrtle, Sherlock?"

"Ah," Sherlock shut his eyes, tightly. "Oh, it's. Um." He had the vague sensation of wandering around the nursery in the dark, searching for an object with his hands. "Mm. Myrtus, like how it sounds. Communus."

"Communis. Very good." Sherlock opened his eyes to catch his brother's smile.

"And their berries are not poison."

"Thank goodness."

Sherlock stuck out a damp hand, imperiously, and Mycroft took it. "Alright, yes, I'll show you."

Decades later, both brothers grown and settled into a comfortable feud- alternately aiding and pretending to ignore one another- Sherlock would retain exactly twelve memories of time spent with Mycroft before he left home for Eton. He would only admit to one or two, and three were recollections he would not share with a living soul (with the dubious exception of John H. Watson) but they each had their place in his Mind Palace, all the same.

This day was wrapped in a dove-colored handkerchief and buried shallowly in a windowbox of flowers, where only he knew to look.

The sky looked like carded wool, and Mycroft made him put on a scarf.

"Where are we looking? What did you find?"

The gravel walk was strewn with shallow puddles. Mycroft walked carefully around them. Sherlock, just as carefully, stepped a yellow Wellington boot into the center of each one. Oily iridescence rode the tiny ripples, swirling pink and kelly greens over the reflected sky. He stared, balanced shakily on one leg.

"What's that? Why does it do that?" Sherlock asked, pointing, but his brother was some ways ahead of him, and he had to trot to catch up.

"What did you find?" he repeated, puffing a little.

Mycroft raised his eyebrows with an expression that was just a few years short of supercilious. "Think, Sherlock."

"It's in - a myrtle bush."

"Yes. In April."

"April is important? So it's not a- ah," Sherlock's words tripped into one another, tongue still learning to keep pace with his thoughts, "- a bicycle tyre, or any old thing." Mycroft's expression was blank, hands tucked into his pockets.

"It's a bird's nest," Sherlock declared.

Tangles of blackberry bush clumped along the low stone wall that had decided to accompany the gravel path in its trek across Holmes property. A stone's throw away, the myrtle bush announced itself with clusters of deep pink. Sherlock started towards it eagerly, but Mycroft snatched at his shoulder.

"Go quietly. A robin will abandon its nest if it is startled before laying."

"But it's April," Sherlock reasoned.

His brother blinked. "What does that have to do with it?"

"You said," Sherlock enunciated in a passing imitation, "robins breed in March."

Mycroft blinked again. "Ah. Well," he huffed. "Go quietly, all the same."

The hedge was wide and spreading, and Sherlock circled along the back while Mycroft examined the front. He'd seen the female and her mate flying in and out of the lowest branches, a few days earlier, but was not sure of the nest's exact location.

They stooped and shuffled, Sherlock determined to make the discovery first. As both explorers were aware, robins nested close to the ground; this was fortunate, as neither of the pair was tall enough to peek over the top of the hedge.

Sherlock could hear but not see his brother's startle and intaken breath.

"What?" he whispered, scrambling upright, dirt and dead leaves sticking to his knees.

"Wait-" Mycroft sounded hesitant, and Sherlock paused for all of a moment before disregarding the warning and circling around to join him.

"I want to see," he began, and paused. Mycroft stood with his back to him, obscuring something on the ground.

"You should, I think," Mycroft said and stepped aside.

A minute centrifuge of bluebottles was busy over a lump in the dirt. The lump was pink, pimpled like unskinned chicken, with tiny black points that prickled through in rows. Sherlock shuffled forward, feet unwilling, and craned over it. Mycroft watched him.

The lump was a dead baby bird.

Sherlock inhaled cautiously through his nose, catching threads of scent- a little bitter, but not overpowering. The smell of grass clippings and the faint flush of myrtle blossom still dominated the air. The bluebottles were very loud. They lingered over the still-closed eyes with a leggy dedication that made Sherlock blink, rapidly.

"What happened?" he demanded, fingers pinching at the knees of his trousers.

Mycroft shook his head. "It might have fallen out. Look, the nest is empty."

Sherlock looked only long enough to see that yes, there was a cup of twigs and some soft lining, and yes, it was empty. His gaze gravitated back to the corpse at his feet.

"But it's," he swallowed. "Ah, it's sort of-" he pointed at the smears of yellow and bile that spread from its froglike abdomen.

"Don't touch it," his brother cautioned. Sherlock bit his lip.

The hatchling's skin was moving, as if beating with multiple, irregular heartbeats. Every time it twitched Sherlock's gut lurched, uncomfortably. Flies moved in and out of fissures unseen. They were such a bright, bright emerald, brighter and shinier than any insect Sherlock had seen.

"Where's its parents?"

"If something disturbed the nest, they probably flew away to make another."

Sherlock nodded. He looked into the hedge at the empty nest and, haltingly, as if releasing one hand from a precipice-grip, reached for it.

"Don't," Mycroft said, hastily.

"Why?" Sherlock stopped, but didn't lower his arm. His fingers were trembling.

"Because if it died in the nest there could be insects, or disease."

"How do you know?"

"We can come back later," Mycroft sighed. "Let's go home, Sherlock."

Dusk was nipping at their heels as they approached the sprawling manor house.

"Did it get sick?" Sherlock asked.

Mycroft shrugged. "There are a lot of ways for infant animals to die. That's why animals keep breeding." He walked behind Sherlock, shepherding.

"We didn't bury it," Sherlock said, thoughtfully, and Mycroft's glance was worried until he continued, "Does that mean it will become a skeleton?"

"It won't become a skeleton, the skeleton was there all along. But nothing will eat the bones, and they won't rot, so they will be exposed, yes."

Sherlock nodded, gravely. After a long silence, punctuated by splashing, he asked, "Does that happen to people?"

Mycroft studied his brother's face in the dim light, upturned and insistent. His curls quirked haphazardly, dark and thick but still baby-fine, like down.

"Yes."

"Even though we put them in boxes?"

"In coffins, yes. That slows the process but- everything made of flesh decays."

"But not mummies."

A smile twitched the corner of Mycroft's mouth. "Well, that's almost correct. Those bodies were specially treated, so some tissues are preserved."

Sherlock fell silent again, watching his boots turn from yellow to grey. He didn't say a word until the muddy path had become fine, even gravel, and the shadow of the front entry stretched to meet them.

"I'm not scared," Sherlock said, without warning.

"I didn't say you were," his brother said, quietly. "Here, don't splash so much. It's getting on your clothes." They were nearly to the house, but he took Sherlock by the hand anyway.

"I'm going back tomorrow," Sherlock announced, hair dripping wet and ears pink from scrubbing.

"Maybe."

Sherlock curled under his covers and watched the ridge of the moon slowly disappear behind his window frame. He fidgeted and thought about puddles, and how some of them had little drowned worms at the bottom. He knew why worms drowned. It was because they breathed through their skin.

A certainty that felt too large to fit under his skin was keeping him awake. It whispered that there was a secret in the dirt and branches and pink burst stomach that was true and important, written in a language that he could not read.

Sherlock fell asleep and dreamt his bed was made of sticks and soft human hair.


End file.
